Carlos Miranda

Malus x domestica Borkh is a key temperate fruit crop globally, but climate change and market demands highlight the need to broaden its narrow genetic base. The collection and conservation of local germplasms support breeding efforts by enabling the development of resilient phenotypes with improved traits. Under this framework, a set of 130 apple accessions (recovered from Northeastern Spain and 14 commercial cultivars were analyzed in terms of 12 phenotypic traits (firmness, SSC, malic acid, enzymatic browning (EB) susceptibility, fructose and glucose content, and phenolic content in peel and pulp). A statistical framework was developed to assess trait stability under shifting climatic conditions and detect significant correlations between climatic variables and phenotypical performance of apple trees. The results revealed a wide phenotypical variation across the studied traits, with the distribution of physicochemical traits strongly influenced in a genotype-dependent manner. A correlation matrix was obtained for studied traits revealing positive correlations between harvest date and SSC, enzymatic browning and firmness. Furthermore, uni- and multifactorial ANOVA revealed that genetic group (GG) is a key factor influencing all measured traits, especially pH, SSC, EB, and browning speed. Several interaction effects were also statistically significant, especially those involving ploidy level, which strongly influenced malic acid content and EB responses. Additionally, significant differences in fructose content were observed depending on peel coloration, and year-to-year phenotypic variation appeared to be predominantly governed by genotypic response to environmental conditions. Moreover, obtention of a mean stability index (D_i) for each trait allowed the identification of ‘Pinova’,’Fuji’ and ‘Gala’ as the most stable cultivars among 11 commercial cultivars. These findings will support future research on development of functional cultivars and selection of ideal genotypes under shifting conditions.

OBJECTIVES/BACKGROUND: Climate change has raised concerns about the imbalance between anthocyanin and sugar levels in grapevines. High temperatures tend to reduce anthocyanin content by inhibiting its synthesis and increasing degradation, while simultaneously enhancing sugar accumulation. The application of elicitors, which promote the anthocyanin biosynthetic pathway, may help alleviate this imbalance. METHODS: To investigate this, a four‐year field trial was conducted on Vitis vinifera cv. Tempranillo to assess the effects of four commercial products: two natural‐based (an antioxidant‐mannitol and an alginic acid‐mannitol products) and two phytohormone‐based (an abscisic acid and an ethephon‐based products). The study evaluated the effect of these treatments on the phenyl propanoid pathway gene expression, various yield parameters, and the content of primary and secondary metabolites. RESULTS: Although none of the treatments consistently increased anthocyanin levels across seasons, the results varied depending on the year. Two products influenced some parameters in specific seasons: the ethephon‐based product, which influenced the anthocyanin‐to‐sugar ratio through the reduction of TSS and induced the expression of key anthocyanin genes, and the natural‐based antioxidant‐mannitol product, which transiently increased the expression of some phenylpropanoid genes. CONCLUSIONS: None of the treatments increased anthocyanin levels across seasons. Ethephon (Fruitel) showed greater effectiveness under temperature stress and reduced sugar accumulation, which may be advantageous in a warming climate. Natural elicitors like antioxidant–mannitol elicitor (Vitalfit) had short‐term effects on gene expression but no lasting impact on anthocyanins. Further research is needed to assess their influence on other polyphenols and their potential for commercial use. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The consolidation of scientific knowledge is based on the accumulation and understanding of previous findings. Nowadays, reviews of the scientific literature have become more effective through the use of meta‐analyses, which are systematic evaluations of the results from multiple studies. Similarly, mega‐analyses, which combine raw data from many studies into a single sample for processing and statistical analysis, are a very powerful tool for analyzing results of heterogeneous origin but require a high level of collaboration between the researchers contributing data. In the framework of a collaborative methodology between different Spanish viticultural research groups, this work uses a mega‐analytical approach to quantify the effects of changes in vine water status on vine vegetative growth, yield, and grape composition, integrating a wide range of growing conditions to obtain robust general trends of vine performance under water deficit. The mean seasonal stem water potential data from the different studies allowed a classification into five levels of water status (no deficit ⟶ mild ⟶ moderate ⟶ high ⟶ severe). A progressive decrease in vegetative growth with increasing deficit was observed, while yield decreased more markedly as water deficit progressed from moderate to high. On the other hand, titratable acidity was more sensitive to variation in water status than sugar concentration, with a greater decrease in titratable acidity when changing from no to moderate deficit. Conversely, increasing water deficit from moderate to high resulted in the greatest increases in grape anthocyanin in the red varieties explored. The results obtained in this work provide solid information on general trends in grapevine response to water deficit that can be used in simulation models or incorporated by grape growers in their decision‐making processes in relation not only to irrigation management but also on other agronomic tools to impact grapevine water status.

Spanish pear germplasm collections are crucial for preservation, research, and breeding efforts. However, genetic diversity and structure is unknown at national level. A coordinated national project analyzed 1251 accessions from 7 Spanish pear collections using an internationally recognized set of 14 SSRs to enhance the utilization of these collections. Key findings included the identification of 760 unique genotypes (490 diploids and 270 triploids). Notably, genotypes represented by a single accession accounted for 49% of the total, indicating high vulnerability of this material. Using a Bayesian clustering method revealed two main genetic groups, G1 containing most foreign cultivars and G2 retaining local Spanish cultivars, which were further divided into two other subgroups using a nested approach, revealing moderate but significant differentiation among them. The populations were renamed according to the origin of the reference samples assigned to each group as ‘South’ (G1.1), ‘Western Europe-1’ (G1.2), ‘Western Europe-2’ (G2.1) and ‘No-Pyrus communis’ (G2.2). The results led to the creation of a ‘generalist’ collection, aiming to maximize genetic diversity representativeness, starting with 68 genotypes but expanding to 111 to achieve better allele recovery. This core collection is a valuable resource for genetic studies and conservation, enhancing efforts to preserve pear biodiversity.

Viral diseases in grapevine cause large economic losses due to decreased irregular yield and unbalanced ripening, and can even lead to plant mortality. There is a large number of grapevine viral agents, and a few of them have a prominent impact due to their worldwide distribution, virulence, and incidence. Although previous research has evaluated variations in viral load between organs and time since infection, there is still a lack of knowledge on how the viruses are transported toward developing tissues. In this work, we present the results of two experiments that contribute to understanding the spread dynamics of four major grapevine viruses (GFLV, GFkV, GLRaV-1, and GLRaV -3). Bud and leaf tissues were sampled from shoots obtained from cv. ‘Garnacha’ cuttings known to be infected with one of these viruses. Bud samples taken at early development stages were used to understand short-distance transport, while leaves taken from young shoots represented long-distance transport, driven mainly through the phloem. Our results show that all viruses were able to invade tissues from the beginning of development. The dissemination ability of GFLV was considerable, as the viral load detected in young organs was as high as in the dormant shoot. Furthermore, for GFLV and GFkV, it was shown that the viral load in young shoots does not follow the general assumption of older tissues accumulating a higher viral load but, conversely, a higher viral load closer to the shoot tip might be driven by the sink strength.

Rootstock election is one of the key decisions when designing a vineyard. Although the research performed to determine the effect they induce in the behaviour of scion varieties is not scarce, it is not easy to have a global idea, as results are usually published scattered. In this work, we re-examine previous research conducted in Spain on rootstock implications on vine agronomic performance through the performance of a meta-analysis (MA). As a result, we were able to integrate the information reported in 20 articles that included rootstock experimentation conducted with 36 different varieties and 47 different rootstocks, totalling 764 individual records. However, when the information was filtered before the meta-analysis, this number decreased to 312 records, for which rootstock Response Ratios (RR) were calculated. The characteristics conferred by the rootstock were more closely related to the rootstock itself, rather than to the characteristics of the Vitis sp. crossing used to create the rootstock. Several rootstocks were identified as more suitable for adapting to future climate change conditions, as far as they were able to moderate sugar accumulation and pH (161-49 C, 41-B MGt and 420A MGt). Meanwhile, 140 Ru and 5-BB were observed to provide high pH and sugar contents despite their high yield. In conclusion, despite being based on data from a single country, the meta-analysis was shown to be a useful tool for enhancing the value of previous research on rootstocks. Combining articles from both peer-reviewed and technical journals helped in the assessment of the implications of different rootstocks, although further steps should be taken to facilitate data integration (harmonisation of measurement and reporting procedures, open data repositories, etc).